<template>
	<view>
		<!-- 搜索框 -->
		<my-search @click="gotoSearch"></my-search>
		<view class="scroll-view-container">
			<!-- 左侧滚动视图区域 -->
			<scroll-view scroll-y="true" class="left-scroll-view" :style="{height:wh +'px'}">
				<block v-for="(item, i) in cateList" :key="i">
					<view :class="['left-scroll-view-item', i == active?'active':'']" @click="activeChange(i)">
						{{item.cat_name}}</view>
				</block>
			</scroll-view>

			<!-- 右侧滚动视图区域 -->
			<scroll-view scroll-y="true" class="right-scroll-view-item" :style="{height:wh +'px'}"
				:scroll-top="scrollTop">
				<view class="cate-lv2" v-for="(item, i) in cateLevel2" :key="i">
					<view class="cate-lv2-title">
						/ {{item.cat_name}} /
					</view>
					<!-- 三级分类列表数据 -->
					<view class="cate-lv3-list">
						<view class="cate-lv3-item" v-for="(item3, i3) in item.children" :key="i3"
							@click="gotoGoodsList(item3)">
							<image :src="'https://api-ugo-web.itheima' + item3.cat_icon.split('itheima')[1]"></image>
							<text>{{item3.cat_name}}</text>
						</view>
					</view>

				</view>
			</scroll-view>
		</view>
	</view>
</template>

<script>
	import badgeMix from '@/mixins/tabbar-badge.js'
	export default {
		// 将 badgeMix 混入到当前的页面中进行使用
		mixins: [badgeMix],
		data() {
			return {
				wh: 0,
				active: 0,
				// 分类列表数据
				cateList: [],
				// 二级分类列表
				cateLevel2: [],
				// 滚动条距离顶部的距离
				scrollTop: 0
			};
		},
		onLoad() {
			// 获取当前系统信息
			const sysInfo = uni.getSystemInfoSync();
			//获取可用高度
			this.wh = sysInfo.windowHeight - 50;

			this.getCateList();
		},
		methods: {
			// 分类列表数据
			async getCateList() {
				const {
					data: res
				} = await uni.$http.get('/categories');
				if (res.meta.status !== 200) return uni.$showMsg();
				this.cateList = res.message;
				// 为二级分类列表重新赋值
				res.message[0].children.forEach(item => {
					item.children.forEach(item2 => {
						item2.cat_icon = 'https://api-ugo-web.itheima' + item2.cat_icon.split(
							'itheima')[1];
					})
				})
				this.cateLevel2 = res.message[0].children;
			},
			// 选中项改变的事件处理函数
			activeChange(i) {
				this.active = i;
				this.scrollTop = this.scrollTop == 0 ? 1 : 0;
				this.cateLevel2 = this.cateList[i].children;
			},
			// 点击三级分类项跳转到商品列表页面
			gotoGoodsList(value) {
				uni.navigateTo({
					url: '/subpkg/goods_list/goods_list?cid=' + value.cat_id
				})
			},
			// 跳转到搜索页面
			gotoSearch() {
				uni.navigateTo({
					url: '/subpkg/search/search'
				})
			}
		}
	}
</script>

<style lang="scss" scoped>
	.scroll-view-container {
		display: flex;

		.left-scroll-view {
			width: 120px;

			.left-scroll-view-item {
				line-height: 60px;
				background-color: #f7f7f7;
				text-align: center;
				font-size: 12px;

				// 激活项的样式
				&.active {
					background-color: #ffffff;
					position: relative;

					// 激活项左侧的红色指示边线
					&::before {
						content: '';
						display: block;
						width: 3px;
						height: 30px;
						background-color: #c00000;
						position: absolute;
						left: 0;
						top: 50%;
						transform: translateY(-50%);
					}
				}
			}
		}

		.right-scroll-view-item {
			.cate-lv2 {
				margin-bottom: 20rpx;

				.cate-lv2-title {
					font-size: 12px;
					font-weight: bold;
					text-align: center;
					padding: 30rpx 0;
				}

				.cate-lv3-list {
					display: flex;
					flex-wrap: wrap;

					.cate-lv3-item {
						width: 33.33%;
						margin-bottom: 10px;
						display: flex;
						flex-direction: column;
						align-items: center;

						image {
							width: 60px;
							height: 60px;
						}

						text {
							font-size: 12px;
						}
					}
				}
			}
		}
	}
</style>
